Just brought my betta home today... He seemed fine in his little pet store cup, and was quite active. Brought him home, acclimated to his new 2 gallon bowl, and set him free. Now, he seems to want to swim with his head down and his tail up... Not all the time, but the majority of the time. Maybe the water quality in his pet store cup was bad? I'm sort of new to this (I've owned a few bettas, but nothing too serious lol), so I'm not really sure what direction to go. Googling his symptoms doesn't return anything.

Also, the water in the bowl seems to want to stay cold... I've had it set up for a few days prior to putting the fish in it, and it barely breaks 70 degrees F. I'm afraid to use an electric fish tank heater, because it's only a 2 gallon bowl. A friend suggested I put a candle under the bowl (it sits on a metal plant stand)... But I'm not sure how well that would work. Some websites suggest a heating pad, but I'd be worried about regulating the temperature. Our apartment stays at 75 degrees, as it's winter here in Kansas City. Any suggestions are appreciated! Thanks in advance!

Just get a heater. They make them for 2 gallons. They sell them for $15 at walmart, and are preset so you don't need to worry about them overheating. Also, a candle doesn't let of enough heat to even change the water temp a bit, and it would be dangerous to have it burning 24/7. Make sure you get a thermometer so you can monitor the temp!

I have a thermometer... One of the sticky-type ones. The walmart near me only had heaters for 10-15 gallon setups, so I didn't even bother looking anywhere else. I guess I just figured that's all they made. :-/ I'll make a trip in the morning to petsmart or petco, and see what they've got. Thanks! :)

Could you post pictures and a better description? It sounds like a buoyancy issue - Swim Bladder Disorder perhaps. If he can't swim down to the bottom of his tank and he occasionally floats, this might be it. Can't be too sure though without some pictures and a better description.

The batteries in my camera are dead... >.< I'd try with my phone, but odds are it won't come out clear enough to be helpful.

Basically, if he's sitting at the surface, he's swimming normally. Head and tail both aligned horizontally. If he goes a bit deeper in the tank, his tail seems to float up over his head... His head slants downward towards the bottom of the bowl, and his tail is more upwards. Like he's got a bubble attached to his bum? He's swimming down to the bottom just fine... It's just like if he swims across the "middle" of the tank, his tail floats.

I'm no expert, but my instinct would be to first deal with the temperature and let him acclimate to his new home. Definitely get a heater, they make ones formulated for small tanks. The under-gravel ones are nice but don't regulate themselves, they just maintain a temperature X degrees above the room temperature. Other ones regulate themselves, but in a small tank keep your eye on the thermometer anyway.

I assume you don't have a filter, since you're saying it's a fishbowl, rather than a tank? If you do have a filter, sometimes the current bothers them so you would want to find a way to baffle the filter and make a slower current.

If he's eating okay and showing no other signs of illness, give him a little time to get used to his home and warm up. If he still continues to swim funny it might be Swim Bladder Disorder, like Tsuhei said. There is a lot of good advice on the forums for treating that, OldFishLady has a lot of good posts about it like the one in this thread:

He seems to be swimming normally this morning... And the temperature in the tank has come up a bit. I moved the bowl to a room that stays warmer, and is a bit closer to a vent for heat. It's at about 73F, which is still a bit low... But getting better. He's eating great, although he's more interested in the bloodworms than the little pellets. He's really active, which is a bit surprising to me given the temperature in the bowl.